Most conventional aircraft engine throttle control systems regulate engine output by means of a throttle lever which is manually positioned by the pilot. The commanded position of the throttle lever is mechanically transmitted to the aircraft engine via a number of cams, gears, pulleys and cables in order to regulate engine output. Some aircraft have autothrottle control systems which adjust the engine output to maintain, for example, a selected airspeed. During autothrottle operation, the throttle lever is repositioned by the autothrottle controller instead of the pilot, so that (i) the position of the throttle lever (i.e., throttle lever angle) is mechanically transmitted to the engine and (ii) the throttle lever angle is consistent with the current output of the engine. During such autothrottle operation, the throttle lever angle provides feedback to the pilot as to the output of the engine. Autothrottle operation is often initiated from a separate control panel in the cockpit.
Disadvantages of these conventional throttle control systems include both their mechanical complexity and their high weight, both of which adversely affect initial manufacture, installation and subsequent maintenance. Furthermore, autothrottle operation and mode selection are often initiated from a separate control panel in the cockpit which detracts somewhat from their convenience.
It is therefore desirable to provide a throttle control system which overcomes the disadvantages of conventional throttle control systems.